This invention relates to a method of switching the copying apparatus from one copying mode to another suitable for use in duplicating a two-color original and an apparatus therefor.
In producing duplicates of a color original or a two-color original having information shown in two colors or black and red, several copying modes are available nowadays. One of them is a copying mode in which all the colors of the original are reproduced with high fidelity. Another copying mode is one in which the reproduction of the original is in the form of an image in black only or in any one color as desired. In still another mode, the information shown in one of the colors in the original is reproduced in the same color but the information shown in the other color is erased.
Various methods have been proposed and are now known for carrying out the copying of a color original or a two-color original in such a manner that the colors of the original are reproduced with high fidelity or that the original is reproduced as an image in black only.
In general office routine in which copying apparatus are utilized, the number of originals containing information shown in black or blue and red on white paper is on an increase, and it is expected that this type of originals will account for the majority of the documents handled in office routine in the near future. The copying modes that have the highest demand in producing duplicates of such two-color originals include a copying mode in which information is copied in two colors with high fidelity, and a copying mode in which the images formed as duplicates are in one color only, such as black or red. The copying mode next in demand is one in which information in one color is reproduced while information in other color is erased.
Copying methods known in the art are all intended to enable one of such copying modes to be carried out. Thus when it is necessary to carry out more than two copying modes, it has hitherto been necessary to have more than two copying apparatus of different types ready for use. This has caused an increase in office expenses.